1. Field of the Invention
The present invention relates to an operation support system for a plant for monitoring and evaluating plant performance and equipment status of various types of power plants, and more particularly, relates to an operation support system for a power plant for monitoring and evaluating plant performance and equipment status using measured data of a thermal power plant.
2. Related Art
As principal running costs for various types of power plants such as a thermal power plant, fuel costs, personnel costs, instrumental maintenance costs, and so forth will be conceived. Suppressing running costs can allow a power plant to be run efficiently.
As costs required for equipment maintenance of a power plant, there are remodeling costs to improve performance of plant component equipment beyond the original performance thereof, reworking costs to recover the performance level of plant component equipment up to the original level thereof, management costs of spare parts, and so forth.
In general, power plant component equipment deteriorates in performance thereof as time passes, as a result, plant thermal efficiency drops, thereby increasing fuel costs. In order to cut back on fuel costs, running at an economical load range in which the optimal plant thermal efficiency can be obtained is preferable, however, running conditions change due to degradation of plant component equipment and the daily running load, so the load range suitable for plant thermal efficiency also changes. Accordingly, with regard to a power plant, it is hard to select and use the appropriate load range in which the optimal plant thermal efficiency can be obtained.
Further, with a power plant, in order to prevent fuel costs from increasing, maintenance of plant component equipment is performed as a measure so as to maintain or improve equipment performance. In order to implement such measures, it is necessary to precisely diagnose and comprehend how far the plant component equipment has deteriorated. In the event of attempting to prevent fuel costs from increasing by maintaining and improving equipment performance with plant component equipment being reworked and remodeled, it is preferable to precisely evaluate, beforehand, cost effects for equipment rework and the like.
However, a power plant is configured of a great number of pieces of plant component equipment, and accordingly, it is difficult to determine cost-to-effect for reworking equipment and the like only with process data that is measured. Moreover, with a power plant, spare parts need to be kept in stock to prepare for accidental equipment damage, so that a damaged portion of equipment can be immediately repaired or reworked so as to resume power generation, which requires management costs for the stock management.
Although running costs for a power plant can be reduced by running the plant more efficiently, there is a close relationship between running costs and equipment maintenance costs, and accordingly, equipment maintenance costs are preferably taken into account so as to make running of a plant more efficient, as well as fuel costs and personnel costs.
On the other hand, in order to keep track of equipment performance of plant component equipment so as to evaluate the running costs, there is the need to have the know-how of the manufacturing equipment manufacturer. Dispatching an equipment manufacturer engineer to a local power plant each time plant component equipment is evaluated not only leads to time and labor problems, but also may let the most appropriate evaluation timing slip by due to restrictions on how often evaluation can be performed.
As conventional technology, the following publications or documents may be listed up.    (1) Japanese Patent Laid-open (KOKAI) Publication No. HEI 4-242123. This discloses a plant performance monitoring device and teaches technique for improving the monitoring precision of power plant record by selecting highly reliable plant performance data. The device monitors performance of respective plant component equipment using plant measurement data.    (2) Japanese Patent Publication No. SHO 62-4526. This discloses a performance monitoring technique of a power plant, i.e., technique for evaluating how plant thermal efficiency is affected, by monitoring plant performance calculation and aged deterioration thereof from process data such as pressure, flow rate, electric power and the like. This evaluates plant thermal efficiency affected by performance degradation of plant component equipment.    (3) Japanese Patent Laid-open (KOKAI) Publication No. HEI 11-229820. This discloses technique for analyzing how change in performance of respective plant component equipment affects the entire power plant, and recovering thermal efficiency by appropriate maintenance and reworking, by improvement of power plant thermal efficiency diagnostic precision.    (4) Japanese Patent Laid-open (KOKAI) Publication No. 2001-263006. This discloses technique for appropriately recovering thermal efficiency by analyzing performance change of respective plant component equipment affecting the entire power plant, and by maintenance and rework.    (5) Japanese Patent Laid-open (KOKAI) Publication No. 2002-122005. This discloses technique for improving plant thermal efficiency diagnostic precision by diagnosing factors for power plant thermal inefficiency using evaluation of a heat balance analysis method and teaches technology to improve precision of performance evaluation of plant component equipment.
However, the diagnostic/monitoring technique for power plants disclosed in the above-described patent documents only diagnoses and evaluates the performance degradation of a power plant and component equipment thereof. That is to say, a technology or means for effectively and integrally evaluating how to rework or remodel plant component equipment is not introduced. Moreover, a technique to quantitatively evaluate how much loss occurs due to performance degradation of plant component equipment, and whether or not there is reworking of plant component equipment, is not introduced either.    (6) Japanese Patent Laid-open (KOKAI) Publication No. 2002-259505. This discloses a data presenting system regarding power equipment, i.e., a data presenting system regarding power equipment capable of inexpensively acquiring evaluation data such as power efficiency, power costs, and so on, over a communication network. This system connects a power plant side with a service center side over a communication network, and the service center side creates and presents evaluation data of power efficiency and power costs (fuel costs per unit generated, over the entire life span of equipment) based on acquired measured data through this network, and bills the plant for reference of the evaluation data.
According to this data presenting system, a data processing process is installed at a place isolated from the power plant side, and receiving measured data and sending evaluation data are performed over a communication network, so that the power plant side can avoid extra investment regarding the data processing process.
With the data presenting system regarding power equipment according to this Patent Document (6), a technique capable of evaluating deterioration of power efficiency and equipment performance over time in the view of fuel costs is disclosed, which compares the current measured process values (the state wherein equipment has deteriorated) with predicted process values of designed performance presuming that the same running conditions as the present will continue (the initially intended state).
With the data presenting system regarding power equipment according to Patent Document (6), transition of process values resulting from of deteriorated equipment performance of plant component equipment is confirmed, and accordingly, it is difficult to quantitatively confirm how many percent the performance of the plant component equipment has deteriorated.
Moreover, plant component equipment of a power plant is reworked in accordance with deterioration due to aging, but not all of the plant component equipment is reworked. With conventional data presenting systems, estimation is computationally performed using as standard for comparison a state wherein all of the plant component equipment has been completely reworked.
However, with a state in which multiple pieces of plant component equipment have deteriorated, in the event of only specific component equipment having being reworked, it is difficult to confirm how far the power efficiency of the power plant or fuel costs has been improved. It is also impossible to perform evaluation in the event of equipment performance having being been improved beyond the designed performance thereof by remodeling the plant component equipment. Furthermore, a technique for quantitatively evaluating whether or not plant component equipment should be reworked is not mentioned at all in the Patent Document (6).